Modification, Structure Design And Electrochemical Performance Of SrLi₂Ti₆O₁₄ Anode Materials

SrLi₂Ti₆O₁₄,the lithium-ion batteries anode material,has not only stable structure,but also lower voltage platform??1.41 V?and higher theoretical specific capacity(262.02 m A h g^-1)than Li₄Ti₅O₁₂,its broad application prospects have attracted widespread attention from researchers.However,the relationship between the structure and performance of such materials still needs to be studied in depth.This paper intends to start from the two aspects of coating modification and morphology control,combining theoretical calculation and experimental characterization to reveal the mechanism of lithium storage and performance improvement,and study the influence of different morphologies on battery performance.Pure SrLi₂Ti₆O₁₄ anode material was synthesized by the sol-gel and solid-state methods,the surface was coated?0,3,5 and 8 wt.%?Al F₃ and Zr O₂?0,3,5 and 8 wt.%?form the SLTO@AF and SLTO@ZO composites by solvent evaporation and solid-state methods,respectively.The results show that the Al F₃ and Zr O₂ coatings layers can inhibit the corrosion of HF,such as other acidic substances in the electrolyte,protect the structural stability of the material,improve the ion diffusion kinetics,and 5wt.%Al F₃ and Zr O₂ composite materials have a longer and more stable voltage platform,faster lithium ion diffusion capacity.In order to study the influence of special structure on its electrochemical performance,the paper stutied has carried out a systematic study on the influence of nano-particles,graded microspheres and hollow graded spherical morphology on battery performance by nano-processing and assembly of SrLi₂Ti₆O₁₄ morphology structure.The results show that the SLTO with hollow graded microsphere structure shortens the free path of carrier diffusion,and the good lithium ion migration elasticity improves the battery performance.On the premise of satisfying the good electrolyte wettability of Hollow-Graded-microspheres,in order to improve its tap density,this paper designs it as a double-layer hollow structure,and regulates its stability through the hydrolysis degree of different amounts of TBOT.The results show that when the addition amount is 2.5 mmol,a double-layer hollow sphere with a diameter of about 500-800 nm,inner diameter of about 400 nm was synthesized.This structure can suppress the volume change,shorten the free path of carrier diffusion,and rapidly diffuse lithium ions.To good buffering,so it has high stability and reversibilityThe above research results show that:for electrode materials,coating the surface and regulating the structure of nanomaterials can effectively improve the electrochemical performance of the materials.